A conventional wrench with an electronic torque display unit is disclosed in U.S. Pat. No. 5,537,877 and shown in FIGS. 7 and 8, wherein the wrench with a case A, a driving unit B, a knocking member C, a push unit D which is located in the case A and in contact with the knocking member C in axial direction such that the knocking member C does not knock the case A before the pre-set torque is reached. An adjustment unit can adjust the initial force of the push unit D to set the value of the pre-set torque.
The push unit D includes a push member D2 which is movable axially in the case A, a spring D1 located between the push member D2 and the knocking member C, a tubular handle F and a rod unit E. The handle F has a connection end rotatably connected with a second end of the case A and the rod unit has a first end inserted into the handle F and a second end of the rod unit E is inserted into the casa A and is connected with the push member D2. The first and second ends of the rod unit E are operated by the handle F and the case A. The push member D2 is moved axially by rotating the handle F.
The torque unit further includes a torque detection unit G which includes bodies G1, G2, a detection member G3, a transferring circuit G4 electrically connected with the detection member G3, and a display unit G5. The bodies G1, G2 are connected to the case A and the detection unit G is connected with the bodies G1, G2. The detection unit G generates a signal which is a signal regarding to the push member D2. The transferring circuit G4 transfers the electronic signals into digital signals which are shown in the display unit G5.
The present invention intends to provide a wrench with an electronic torque display unit which improves shortcomings such as inconvenience of use and less precise of the conventional torque display unit for wrenches.